Recreational vehicles commonly employ slide-out rooms to allow the recreational vehicle greater living space when parked. Throughout the development of the mechanisms for these slide-out rooms, designers have sought to improve slide-out designs by making the slide-out area of the vehicle highly usable both when contracted and extended, by designing stable slide-out rooms that contract and extend smoothly, and by designing rooms that can be fabricated with a minimum of parts, labor, and modifications to the chassis and floor of the recreational vehicle.
Several slide-out room designs employ a mechanism whereby the bottom surface of the slide-out is extended along the top surface of the vehicle to arrive at the extended position. For example, U.S. Pat. No. 5,902,001 to Schneider discloses a mechanism whereby the slide-out room extends along the stationary floor while attached to a pair of powered rails, which actuate the movement of the slide-out. Upon arriving at the fully extended position, the room is lowered along a first, short inclined-plane to its final position, having its floor lie flush with the stationary floor. On contraction, a mating, second inclined-plane on the slide-out room serves to lift the slide-out room along the first inclined-plane.
Another such mechanism is disclosed by U.S. Pat. No. 6,202,362 to McManus et al. The McManus mechanism, similarly, employs a system of dual, mating inclined-planes wherein the first inclined-plane is located at the edge of the stationary portion of floor and the second inclined-plane is located at the edge of the slide-out room floor. In McManus' disclosure, however, the inclined planes traverse a short vertical distance over a relatively long horizontal distance, thus, resulting in a smoother descent or ascent of the slide-out room. Also, the invention includes flat surfaces adjacent to each inclined-plane such that, when extended, the flat surface of the slide-out room lies upon the flat surface of the stationary room for support, thus, allowing for greater support of the slide-out room. The flat surface included with the slide-out room floor, however, is undesirable as it acts as a protruding “tongue” when the slide-out room is contracted.
Another such mechanism is disclosed by U.S. Pat. No. 6,402,216 to McManus et al., which discloses a slide-out room mechanism including a double inclined-plane attached to the slide-out room. By including a plane-on both lateral ends of the slide-out room, the device maintains the same slide-out room height when the room is contracted and when extended. The slide-out room is temporarily elevated while in the intermediate positions. Another mechanism, disclosed in U.S. Pat. No. 6,619,713 to Eichhorn, uses a flat, thin floor for the slide-out room that is not lowered when fully extended. Thus, the slide-out room remains at a constant height that is slightly higher than the stationary floor.
All of the above mechanisms, because they rely upon flat surfaces to slide upon and inclined places for elevating and lowering the slide-out room, fail to disclose a mechanism that is smooth and stable in its operation. Thus, another class of slide-out room mechanisms has been developed which employs rollers in order to facilitate the extending and contracting of the room.
One such mechanism is disclosed by U.S. Pat. No. 6,108,983 to Dewald, Jr. et al. Dewald's invention includes a floor which slides along the stationary floor and drops down a ramp to arrive at its extended position, flush with the stationary floor. Like many current systems, Dewald's invention uses a roller at the inward edge of the slide-out room floor to articulate along the surface of the stationary room floor. On being extended, the roller descends an incline-plane located at the outward edge of the stationary floor, in order to lower the slide-out room to its final position, which lies flush with the stationary floor. On contraction of the slide-out room, the wheel articulates along the incline-plane to ascend and return to its position, above the stationary floor. The inherent disadvantages of this and similar mechanism is that numerous cut outs and modifications must be made to the chassis of the stationary floor of the recreational vehicle in order to accommodate the inclined-plane and roller on the slide-out room floor.
Similarly, U.S. Pat. No. 6,619,714 to Schneider et al. discloses an elaborate mechanism employing rollers on the stationary floor of the recreational vehicle in order to facilitate the extension and contraction of the slide-out room. Again, like Dewald's disclosure above, this system requires numerous undesirable modifications to the chassis and stationary floor of the recreational vehicle as well as additional parts. The current state of the art in slide-out room mechanism is similar to the above devices and includes many of the above shortcomings because the rollers are placed floor of the sliding section.
One mechanism that improves upon these mechanisms is disclosed in U.S. Pat. No. 6,729,669 to McManus et al., which discloses a slide-out room mechanism wherein a pair of rollers are attached to the chassis and assist the slide-out room and assist the sliding of the room. This mechanism, however, also suffers from many of the shortcomings of the above inventions because the rolling mechanism is complex and requires many additional parts and modifications to the stationary floor in order to function. Specifically, the rolling mechanism in the patent is included as part of a lifting/lowering mechanism to raise the slide-out room to its contracted position. Thus, rather than reducing the number of parts and the complexity of the slide-out room mechanism, as is commonly desired by manufactures, the disclosed mechanism is quite complex.
Thus, there remains a long-felt need in the art for a slide-out room mechanism that provides smooth and stable operation while requiring a minimum of parts and modifications to the chassis and stationary floor of the recreational vehicle.